Apparatus for making seamless tubular articles



Oct. 24,1933. I w. H. ENGELBEIRTZ I 1,932,266

' APPARATUS FOR MAKING SEAMLESS TUBULAR ARTICLES Filed Aug. 5, 1931 as 4o -42 $3 3 Q Q Q INVENTOR by the so-called p a heated cup-shape Patented Oct. 24, 1933 APPARATUS FOR MAKING SEAMLESS TUBULAR ARTICLES William H. Engelbertz, Youngstown, Ohio Application August 3, 1931. Serial No. 554,677

5 Claims.

This invention relates to the manufacture of seamless metal tubes, or other seamless tubular articles.

It is generally known that seamless metal tubes are produced from cup-shaped billets ushbench apparatus, in

d billet is placed on the front which end of a mandrel and forced through a set of ring-shaped dies ameter.

The cost with successively decreasing dis of .such a process are very high as the enormous axial stresses frequently upset the front end 0 be reshaped, and tear the f the mandrel, which must bottom of the billet to be stretched, thus rendering the billet practically useless for this stantial wear of ,the friction of the passing ameter, occurs in such a purpose.

dies caused by the sliding Moreover, a subbillet to be reduced in diprocess and, therefore,

these dies must frequently be exchanged. Furhigh stress is imposed on the thermore, a very material-fibers of the billet being forced through a succession of ring-shaped dies, thus making the use of low-grade material for the production of seamless tubes impossible.

The general object of the present invention is to provide a method and apparatus to eliminate the above mentioned set-backs of the pushbench process, thereby d turing costs of seam ufacture of such claims.

readily comprehen reference should be drawing. I wish ecreasing the high manufacless tubes, and effecting mangoods in a more efficient, expeditious and economical manner.

All advantages comprehended by this invention will be specifically described hereinafter, and will be particularly pointed out in the appended To enable those skilled in the art to d and practice this invention, made to the accompanying have it understood that it is not my intention to confine or limit myself to any specific details of construction described or illustrated herein, since changes and alterations st themselves to those skilled will readily sugge in this art without departing from the spirit and scope of the invention.

Seamless tubes, or other tubular articles to be manufactured according to the invention are preferably made from square or round billets, previously heated and shaped to cup-like form, that is, a hollow body with bottom at one end. shaped billets is placed on the One of these cupfront end of a mandrel and, thereafter, is formed to a tube of desired cross-section by forcing a number of non-driven roll sets, generally mounted upon a common frame, over mandrel which is h forming process.

the billet on said eld stationary during the Each of said roll sets includes two or more rolls, and the successive roll sets show a decrease in the size of their roll grooves to gradually shape and form the cup-like billet to approximately the desired outside diameter of the tube to be made.

The shaped tube hugs tightly to the mandrel and, therefore, the mandrel and tube are jointly conveyed to any suitable 1y expand the diameter of means adapted to slightthe tube on the mandrel, for instance, a reeling machine of old and well known design, in which a pair of cross rolls increase the tube diameter slightly and, simultaneously, equalize the tube wall. Suitable means then strip the tube from latter is held stationary,

the mandrel while the whereupon the tube may be conveyed to cooperating roll sets which reduce and true its diameter.

The accompanying ferred embodiment of the drawing shows one preinvention in somewhat diagrammatical form in which-Fig. 1 is a view of a part of the apparatus, in a stationary position and showing the mandrel the shiftable frame mounting sets of rolls, advancing toward the mandrel to form and front end of said mandrel, a view of the same parts roll the billet, placed on the into a tube. Fig. 2 is of the apparatus disclosed in Fig. l, the shiftable frame mounting the sets of rolls being advanced, and said rolls after having passed over the billet and shaped the same into a tube.

Fig. 3 shows the mandrel and the tube, clinging thereto, passing the cross rolls of a reeling machine and, in dotted lines, the mandrel and tube being stopped in their advance after passing the cross rolls. tion of mandrel and tube Fig. 4 shows the separain progress, and cooperating roll sets which may reduce and true the tube.

The stationary mandrel 1, supporting on its front end the cup-shaped billet 2, is provided with an extension or mandrel holder 3 which, in turn, has at its rear end a stationary abutment 4. {The slidable guides 5 to 10, inclusive, serve to support the mandrel in proper position, and to avoid bending of the mandrel and its extension when shiftable frame 11, driven by rack 12 over pinion 13, supporting sets of non-driven rolls 14 to 20, inclusive, is advanced in direction of arrow A (Fig. 1) to shape tube 21, shown in Fig. 2.

and roll billet 2 to a The use of slidable guides 5 to 10, to support the mandrel and its holder, constitutes only an example of how said mandrel and its extension can be prevented from suitable means may be e purpose, in. accordance w bending. Therefore, any

mployed to serve this ith the invention,

To perform the tube-forming operation, any desired number of roll sets may be used, and the roll grooves of the succeeding sets "should be of decreasing cross section so that the outside diameter of billet 2 is gradually decreased when the rolls pass over it. The rolls in the successive sets are so arranged that the parts of billet 2 between the circumferentially contacting points of the roll-grooves are covered'by the grooves of the succeeding rolls. The mandrel 1 remains stationary, while billet 2 is rolled over said mandrel into a tube of desired wall thickness and length, and is held against backward motion by the mandrel shaft or holder 3 which, in turn, is held stationary by the abutment 4.

Upon termination of the rolling operation, frame 11 with roll sets 14 to 20, inclusive, is shifted back to its initial position by reversing the drive of rack 12, thereby shifting mandrel 1 with adhering tube 21-, supported by rollers 46 and 4'7, in direction of arrow B (Fig. 2) by means of grippers 22, attached to frame 11. The mandrel and tube will be released by said grippers when reaching the conveying rollers 23 and 24, located at the inlet-side of cross rolls 25 of a reeling machine. Said cross rolls then grip tube 21 with mandrel 1 and, while slightly expanding the tube diameter, equalize the tube wall.

After the reeling operation, tube 21, with mandrel 1 still. inside, is conveyed in the direction of arrow C (Fig. 3) until it reaches rollers 26 to 29, inclusive, where the advancement of the tube is temporarily checked by stop 30 until the mandrel is engaged, that is, arrested by stop 31. Said stops are connected by suitable means (not shown on the drawing) to operate alternately, that is, while stop 30 is lowered stop 31 is raised, and vice versa. By the lowering of stop 30, as shown in Fig. i, the rollers 32 and 33 are pressed downward upon tube 21, thereby cooperating with the driven rollers 28 and 34 to strip tube 21 off mandrel 1.

Then the released tube, after its ends have been cut off bya hot-saw or other suitable means (not shown on the drawing), while advancing in the direction of arrow D (Fig. l) over conveying rollers 35, 36 and. 37, may pass the roll sets 38 to 42, inclusive, in order to be reduced or trued to the desired diameter. Any suitable number of roll sets may be employed for this purpose, and each roll set may comprise at least two or more rolls. Tube 21 may be reheated, if desired. be fore passing said roll sets. The tube thus finished then is received by rollers 43, 44. 45.

What I claim is:

1. Apparatus for making seamless tubular ar ticles from cup-shaped billets, comprising a mandrel adapted to support at its front end a cupshaped billet, means to hold said mandrel against longitudinal motion in backward direction, longitudinally shiftable elongating means adapted to roll said billet upon said mandrel into a tube by forcing said elongating means over said billet, means to slightly expand the diameter of said tube on said mandrel, means to separate said mandrel from said tube by advancing said tube while holding said mandrel stationary, and rolling means in line with, and receiving said tube from, said separating means, to further reduce and true said tube.

2. Apparatus for forming seamless tubing from cup-shaped billets, comprising a mandrel adapted to support at its forward end a cup-shaped billet, means to hold said mandrel at its rear end against longitudinal backward motion, a 1ongitudinally shiftable frame supporting sets of cooperating rolls adapted to roll said billet into a tube by shifting said frame toward and over said mandrel, means, bearing on said frame, to advance said mandrel and tube in forward direction by moving back said frame to its initial position, means to slightly expand the diameter of said tube, means to separate said mandrel from said tube by advancing said tube While holding said mandrel stationary, and cooperating rolls to further shape and true said tube.

3. Apparatus for rolling seamless tubes from cup-like billets, comprising a mandrel adapted to support at its front end a cup-like billet, a sta tionary mandrel-holder supported by an abutment at its rear end, preventing said mandrel from longitudinal backward motion, shiftable means to support said mandrel and mandrelholder and to prevent said mandrel and mandrelholder from bending, a frame supporting sets of cooperating rolls shiftable to force said rolls over said billet to form saidbillet into a tube over said mandrel, said frame having means thereon to ad vance said mandrel and tube in a forward direction while the frame is returning to its initial position, means to slightly expand the diameter of said tube on said mandrel, shiftable holding means to stop the motion of said mandrel, and positive means to advance the tube while said mandrel is arrested by said holding means, thus separating said mandrel and tube.

4.. Apparatus for forming seamless tubular articles from cup-shaped billets, comprising a mandrel adapted to support at its front end a cupshaped billet, means to prevent backward motion of said mandrel, longitudinally shiftable rolling means to form a tube from said billet on said mandrel while forcing said rolling means over said billet and mandrel, means operated by the return of said rolling means to its initial position to advance said mandrel and tube to a conveyor, means at the end of said conveyor to slightly expand the diameter of said tube on said mandrel, means to further advance said tube and arrest said mandrel, and cooperating rolls to further shape said tube to the desired size.

5. Apparatus for forming seamless tubular articles from cup-shaped billets, comprising a mandrel adapted to support at its front end a cup shaped billet, means to hold said mandrel against backward motion, longitudinally shiftable rolling means adapted to roll said billet upon said mandrel into a tube, means operated by the return of said rolling means to its initial position to advance said mandrel and tube in a forward direc-- tion to a conveyer, means at the end of said conveyor to slightly expand the diameter of said tube on said mandrel, means to convey said tube and said mandrel to a separating device including separate stops adapted to stop the forward motion of said tube and mandrel and grip the rear end of said mandrel, cooperating conveying means to advance said tube while said mandrel is held stationary, thus separating said mandrel from said tube, and cooperating rolls to further reduce and true the diameter of said tube, all of said working steps being performed without reheating said billet. or said tube.

WILLIAM H. ENGELBERTZ. 

